Marking pen



FIG. 1 is a perspective view of a marking pen showing my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a left side elevation view thereof;

FIG. 6 is a right side elevation view thereof;

FIG. 7 is a front elevation view of FIG. 1, with the tip of the marking pen extended; and,

FIG. 8 is a bottom plan view of FIG. 3, with the tip of the marking pen extended. 

The ornamental design for a marking pen, as shown and described. 